Thiopental Protects Human T Lymphocytes from Apoptosis in Vitro via the Expression of Heat Shock Protein 70

Anaesthesiologische Universitaetsklinik, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
Journal of Pharmacology and Experimental Therapeutics (Impact Factor: 3.97). 05/2008; 325(1):217-25. DOI: 10.1124/jpet.107.133108
Source: PubMed


Barbiturates, which are used for the treatment of intracranial hypertension after severe head injury, have been associated with anti-inflammatory side effects. Although all barbiturates inhibit T-cell function, only thiobarbiturates markedly reduce the activation of the transcription factor nuclear factor-kappaB (NF-kappaB). Various pharmacologic inhibitors of the NF-kappaB pathway are concomitant nonthermal inducers of the heat shock response (HSR), a cellular defense system that is associated with protection of cells and organs. We hypothesize that thiopental mediates cytoprotection by inducing the HSR. Human CD3(+) T lymphocytes were incubated with thiopental, pentobarbital, etomidate, ketamine, midazolam, or propofol. Human Jurkat T cells were transfected with small interfering RNA (siRNA) targeting heat 70-kDa shock protein (hsp 70) before thiopental incubation. Apoptosis was induced by staurosporine. DNA binding activity of HSF-1 was analyzed by electrophoretic mobility shift assay; mRNA expression of hsp27, -32, -70, and -90 was analyzed by Northern blot, and protein expression of hsp70 was analyzed by Western blot and flow cytometry after fluorescein isothiocyanate (FITC)-hsp70-antibody staining. Apoptosis was assessed by flow cytometry after annexin V-FITC or annexin V-phycoerythrin staining. Activity of caspase-3 was measured by fluorogenic caspase activity assay. Thiopental induced hsp27, -70, and -90 but not hsp32 mRNA expression as well as hsp70 protein expression. Thiopental dose-dependently activated the DNA binding activity of HSF-1, whereas other substances investigated had no effect. In addition, pretreatment with thiopental significantly attenuated staurosporine-induced apoptosis and caspase-like activity. Transfection with hsp70-siRNA before thiopental treatment reduced this attenuation. Thiopental specifically and differentially induces a heat shock response, and it mediates cytoprotection via the expression of hsp70 in human T lymphocytes.

Download full-text


Available from: David Schibilsky, Jan 10, 2014
  • Source
    • "However, a beneficial effect on neurological outcome is unproven and a critically discussed issue, mainly because of severe medical complications [36]. Although thiopental has been associated with inhibition of neuronal apoptosis [37], reduced excitotoxicity [38], [39], radical scavenging [40]–[42], and the induction of cytoprotective heat shock proteins [43], these experimental studies do not sufficiently explain major neuroprotective physiological observations such as decreased cerebral metabolism and reduced oxygen demand [44], [45]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Ischemic and traumatic brain injury is associated with increased risk for death and disability. The inhibition of penumbral tissue damage has been recognized as a target for therapeutic intervention, because cellular injury evolves progressively upon ATP-depletion and loss of ion homeostasis. In patients, thiopental is used to treat refractory intracranial hypertension by reducing intracranial pressure and cerebral metabolic demands; however, therapeutic benefits of thiopental-treatment are controversially discussed. In the present study we identified fundamental neuroprotective molecular mechanisms mediated by thiopental. Here we show that thiopental inhibits global protein synthesis, which preserves the intracellular energy metabolite content in oxygen-deprived human neuronal SK-N-SH cells or primary mouse cortical neurons and thus ameliorates hypoxic cell damage. Sensitivity to hypoxic damage was restored by pharmacologic repression of eukaryotic elongation factor 2 kinase. Translational inhibition was mediated by calcium influx, activation of the AMP-activated protein kinase, and inhibitory phosphorylation of eukaryotic elongation factor 2. Our results explain the reduction of cerebral metabolic demands during thiopental treatment. Cycloheximide also protected neurons from hypoxic cell death, indicating that translational inhibitors may generally reduce secondary brain injury. In conclusion our study demonstrates that therapeutic inhibition of global protein synthesis protects neurons from hypoxic damage by preserving energy balance in oxygen-deprived cells. Molecular evidence for thiopental-mediated neuroprotection favours a positive clinical evaluation of barbiturate treatment. The chemical structure of thiopental could represent a pharmacologically relevant scaffold for the development of new organ-protective compounds to ameliorate tissue damage when oxygen availability is limited.
    Full-text · Article · Oct 2013 · PLoS ONE
  • Source
    • "b) Thiopental: is the prototype barbiturate used for anesthesia with an apoptotic mechanism by GABA-A agonistic action (64); also, through inducing lymphocyte death by "a CD95-independent mechanism" (65) and by "attenuated staurosporine-induced apoptosis and caspase-like activity" (66, 67); of course, the latter effect might be cardioprotective and against cardiomyocyte apoptosis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The modern practice of anesthesia is highly dependent ona group of anesthetic drugs which many of them are metabolized in the liver. The liver, of course, usually tolerates this burden. However, this is not always an unbroken rule. Anesthetic induced apoptosis has gained great concern during the last years; especially considering the neurologic system. However, we have evidence that there is some concern regarding their effects on the liver cells. Fortunately not all the anesthetics are blamed and even some could be used safely, based on the available evidence. Besides, there are some novel agents, yet under research, which could affect the future of anesthetic agents' fate regarding their hepatic effects.
    Full-text · Article · Aug 2013 · Hepatitis Monthly

  • No preview · Article ·
Show more